Devlog ·

Milestones — April 25, 2026

~4 min read · 1022 words

A single-day batch that pushed the PS1 port across several long-standing unknowns: working TTY, an instrumentable perf module wired into a Docker regtest harness, a real on-PS1 pause menu, a holiday-coverage design expansion from 4 to 35, a hand-rolled SPI controller driver replacing the broken BIOS pad path, and the start of memory-card-backed user settings. What follows is the day’s archeology in bullets, with links to the locked-in design docs.

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1. Working PS1 printf() to TTY

  • PSn00bSDK + DuckStation now reliably emits printf() output to TTY logs. Earlier in the project this had been intermittent / unreliable — the same call would surface in some build/runtime configurations and silently drop in others.
  • This is the single largest unblocker for the rest of today’s work. Instrument-based perf debugging, JCPERF/JCPERF2 line mining, and one-shot snapshots like JCPAUSE are all only useful once printf is trustworthy.
  • See docs/ps1/current-status.md “Known limitations” for the older caveat (gated probes only); that paragraph is now stale and is being updated alongside this milestone.

2. Performance baseline + Docker regtest pipeline

  • New src/ps1_perf.c/h module landed with a level-gated logging API: ps1PerfSetLevel(level) switches between OFF / SUMMARY / DETAIL / DEBUG. Boot-token aliases (perf, perf-detail, perf-debug) are parsed by the existing BOOTMODE.TXT path so an external operator can pick a level without recompiling.
  • TTY emits structured JCPERF / JCPERF2 lines per scene (loop_vb, target_vb, blocking_vb, hidden_vb, due_misses, render/held entry counts, CD bytes, restore/upload bytes, etc.). These lines are designed to be mined by an external agent — every field is a stable, greppable key=value pair.
  • scripts/regtest-*.sh ride on top of the existing DuckStation-headless Docker image. Frames dump on a fixed interval, TTY captures to stdout, state hashes capture at exit. Combined, this gives a single command that produces both visual diff inputs and machine-readable perf baselines for a regression run.
  • See the performance optimization plan for the optimization backlog being driven by these numbers.

3. Pause menu — first real user-facing UI (SHIPPED)

  • Pressing Start now opens an overlay during scene playback. Items: Resume / Sound / Day-Night override (AUTO/DAY/NIGHT) / Holiday override (AUTO/NONE/HALLOWEEN/ST PATRICK/CHRISTMAS/NEW YEAR) / Save Settings to Memcard / Reset Screensaver Loop / Next Scene / TTY Perf Log (OFF/SUMMARY/DETAIL/DEBUG) / Debug Info / Set Time-Date.
  • Custom font path (shipped): embedded 8x8 ASCII glyph table (pmFontBits[96][8] in src/pause_menu.c), pre-doubled to 16x16 at upload time (pmUploadFont), drawn glyph-by-glyph via manual SPRT primitives (pmTextDrawChar). PSn00bSDK’s FntFlush was empirically broken in the scene-runtime context — it accumulates primitives without producing any visible pixels — so the in-tree font path replaces it entirely.
  • Panel rendering (shipped): translucent dim quad (POLY_F4 semi-trans black) under an opaque purple panel with 12-pixel chamfered corner cutouts (3-rect rounded-rectangle look), drawn over the live scene every paused frame.
  • Sound mute (shipped): SpuSetCommonMasterVolume is not honored by DuckStation HLE, so the mute path zeros every voice volume + CD vol + master vol and clears the master-enable bit in SPU_CTRL via direct register writes.
  • Day/Night and Holiday overrides (shipped): flow into fgLoopApplyVariant in src/jc_reborn.c with priority explicit menu override > Set Time/Date soft override > random.
  • Files: src/pause_menu.c/h. Design: pause menu design.

4. Holiday expansion — 4 → 35 design

  • The existing four holidays (Halloween, St Patrick’s, Christmas, New Year) covered fewer than half of the calendar months. The new design doc proposes 35 US-centric holidays with at least one per month and an average of about three.
  • Mix is federal + pop-culture + seasonal (e.g. Pi Day, Talk Like a Pirate Day, Star Wars Day, Moon Landing Day) so the screensaver always feels seasonally alive rather than dead-stretches between the four legacy events.
  • Design: holiday expansion design. Implementation is not in this batch.

5. SPI direct controller polling

  • The BIOS pad system (InitPAD / StartPAD) was empirically broken in our PSn00bSDK 0.24 + DuckStation environment. Replaced with PSn00bSDK’s reference SPI driver — timer-2 + SIO0 IRQ-driven, polling at 250 Hz.
  • One critical bug found while porting: spicyjpeg’s reference uses tx_len=4, but DuckStation’s controller emulation only delivers button bytes when the full 5-byte poll sequence comes from the TX buffer (tx_len=5). That single off-by-one is what surfaced as “Start does nothing” during early pause-menu wiring.
  • Files: src/spi.c/h, integrated into src/events_ps1.c. The pause menu, day-night override, and any future input feature all sit on top of this driver.

6. Memcard support (SHIPPED)

  • src/memcard.c/h saves user pause-menu settings (sound mute, day/night override, holiday override, soft time/date) to a single 8 KB block on memcard slot 1, file name BASLUS-99999JCREB.
  • Avoids the BIOS card driver entirely (InitCARD / StartCARD / _bu_init / file API). The BIOS driver installs a persistent VBlank handler that fights our 250 Hz SPI controller-polling timer and tanks scene framerate. Instead, memcard I/O rides on top of our existing SPI driver via SPI_CreateRequest queue + raw byte sequencing per the nocash memcard protocol.
  • During memcard ops the SPI poll rate drops 250 Hz → 50 Hz: a single card transaction is ~5.5 ms, longer than the 4 ms timer-2 tick that drives the controller poller, so we widen the tick to give the card exclusive SPI bus time.
  • Save block carries a proper PS1 save header (SC magic + title + icon frame count + 16-color CLUT) with a hand-drawn 16x16 palm-tree icon, so the save shows up in the BIOS Memory Card Manager like a normal game save.
  • Boot-time auto-load: if a save exists, settings are restored before the scene loop starts. The Save Settings menu entry writes; reads happen automatically at boot.

7. TTY log prefixes

  • The complete set of greppable log-line prefixes after this batch: JCSPI (controller driver), JCPAD (pad layer), JCBOOT (boot / bootmode), JCPERF / JCPERF2 (perf module), JCPAUSE (pause-menu one-shot snapshot), JCMC (memcard). All are stable key=value pairs intended for external perf-debugging agents.

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